1. Field of the Invention
This application relates to wireless multi-hop networks and more particularly to utilization of access protocols in wireless multi-hop networks.
2. Description of the Related Art
Quality of Service (QoS) in multi-hop wireless networks is difficult to support for several reasons. Wireless communication is broadcast in nature and transmissions by any node nearby may cause contention for wireless access and delay a node's transmissions. Contention for channel access is usually resolved by a protocol involving random decisions. Thus, who gets channel access and when is not deterministic. Such dynamics in multi-hop wireless networks makes supporting parameterized QoS, such as guaranteeing delay bound, extremely difficult. The dynamic nature of traffic flows combined with dynamics in network forwarding topology in such a network also make QoS provisioning difficult.
Current QoS solutions focus on only providing Differentiated Service type of QoS. The capability is already supported by commercial off the shelf wireless LAN products. However, even in single hop wireless networks such as infrastructure mode WLAN, such an approach only improves QoS of traffic statistically for one class relative to other traffic classes, but not among traffic flows within the same class. In a multi-hop network, the situation is much worse because various uncertainties for each individual communication link are now compounded over all links along a forwarding path.